Polymer80 AR15 80% Receiver w/ Jig Kit - polymer 80
About this product
The Polymer80 AR15 80% Receiver w/ Jig Kit is an unfinished polymer lower receiver requiring machining to complete an AR-15 build. It includes a jig for precise drilling and milling operations. This kit allows builders to create a firearm without serialization for personal use, adhering to federal regulations for 80% receivers.
What is the Polymer80 AR15 80% Receiver w/ Jig Kit used for?
It is used for completing an AR-15 lower receiver through machining, enabling a custom build without serialization. The jig ensures accurate hole placement for trigger and fire control groups. Required tools include a drill press and end mill, taking approximately 2-3 hours for a skilled user.
How does the Polymer80 AR15 80% Receiver w/ Jig Kit compare to the .308 80% Lower – Billet?
The Polymer80 AR15 receiver is 30% lighter at 8.2 oz versus the billet aluminum .308 lower's 11.7 oz, but sacrifices durability for weight savings. The billet alternative offers higher impact resistance for larger calibers, making it better for heavy-use builds like the .308 80% Lower – Billet.
What does it weigh and what are the dimensions?
It weighs 8.2 oz and measures 7.5 inches in length, 2.1 inches in width, and 1.8 inches in height. These dimensions align with MIL-SPEC AR-15 lower receiver standards, ensuring compatibility with most upper assemblies. The polymer construction contributes to the reduced weight compared to aluminum counterparts.
Who is this NOT for?
This kit is not for beginners without machining experience or those in jurisdictions restricting 80% receivers. It requires precise tooling and knowledge of firearm laws; errors can render the receiver unusable. For guidance on compliance, refer to Calculating Polymer Frame Warranty Coverage Limits.
What's in the box?
The box contains one polymer 80% lower receiver, one aluminum jig, three drill bits (3/8", 5/16", and 1/4"), and installation screws. The jig is pre-aligned for AR-15 fire control group holes, reducing setup time. No tools or lubricants are included; see Best Lubricants for Polymer Slide Surfaces for recommendations.
Is the Polymer80 AR15 80% Receiver w/ Jig Kit worth it at $60.99?
At $60.99, it is worth it for experienced builders seeking a lightweight, cost-effective option. It avoids FFL fees and allows customization, but requires additional tool investments. Compared to finished lowers costing $100+, it saves money but adds labor, making it ideal for DIY enthusiasts.
Specs at a glance
Video review
Pros & cons
What works
- Weighs 8.2 oz — 30% lighter than aluminum .308 lowers
- Includes pre-aligned jig for accurate hole placement within 0.005 inches tolerance
- Costs $60.99 — avoids $50+ FFL fees on finished receivers
- Compatible with MIL-SPEC AR-15 uppers and buffers
Trade-offs
- Requires drill press and end mill — adds $150+ tool cost
- Polymer material has lower impact resistance than billet aluminum — not ideal for high-stress builds
- No serialization — limits resale and may conflict with state laws like California's
- Jig wear after 3-4 uses reduces hole accuracy — replacement jig costs $25
Expert review
Key attributes
| Caliber | 5.56 NATO |
| Material | Polymer |
| Weight | 8.2 oz |
| Length | 7.5 in |
| Width | 2.1 in |
| Height | 1.8 in |
| Finish | Unfinished |
| Compliance | 80% receiver |
Frequently asked questions
- Is it compatible with standard AR-15 upper receivers?
- Yes, it is compatible with MIL-SPEC AR-15 upper receivers. The rear takedown pin hole is spaced at 0.250 inches, matching industry standards. Ensure proper alignment during installation to avoid fit issues.
- Does it fit buffer tubes for carbine stocks?
- Yes, it accepts standard carbine buffer tubes with a 1-3/16 inch thread pitch. The receiver thread depth is 1.5 inches, accommodating most commercial buffer assemblies. Use a torque wrench set to 35 ft-lbs for secure installation.
- How long does shipping take?
- Shipping typically takes 5-7 business days within the continental US via USPS Priority Mail. International orders may require up to 14 days and are subject to customs regulations. Tracking is provided within 24 hours of purchase.
- Can I return it if it doesn't fit?
- No, returns are not accepted due to the nature of 80% receivers and potential alterations. All sales are final once machining begins. Inspect for defects upon receipt and contact support within 48 hours for replacements.
- Does this work with drop-in triggers like Timney?
- Yes, it works with drop-in triggers such as the Timney Calvin Elite. The fire control group pocket dimensions are 1.125 inches wide, compatible with most aftermarket units. Minor fitting may be required for seamless operation.